Notes_03_Writing and Naming Compounds

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Chemistry Notes

Unit 3: Writing and Naming Compounds

Name: _________________________

Binary Ionic Type I Compounds: Compounds involving just two elements: One element is a metal with only one valence state and the other element is a nonmetal.

To name these types of compounds:

1. Put the metal first, then the nonmetal. 2. Change the ending of the nonmetal to “ide.”

1. Name the following compounds:

a. NaCl: ________________________________

b. ZnO: ________________________________

c. Cd3N2: ________________________________

d. Mg3N2: ________________________________

e. SrBr2: ________________________________

To write the formula of these types of compounds: 1. Write the symbols with the metal first. 2. Balance the charges with subscripts.

2. Write the formula for the following compounds:

a. Strontium Oxide: __________

b. Scandium Chloride: __________

c. Potassium Sulfide: __________

d. Barium Phosphide: __________

e. Francium Oxide: __________

Binary Ionic Type II (Roman numeral) Compounds: Compounds involving just two elements: One element is a metal with more than one valence state and the other element is a nonmetal.

To write the formula of these types of compounds: 1. Write the symbols with the metal first. 2. Balance the charges with subscripts.

a. Niobium (III) Iodide: __________

b. Iron (III) Sulfide: __________

c. Cobalt (II) Oxide: __________

d. Nickel (II) Phosphide: __________

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1. Put the metal first, then the nonmetal. 2. Change the ending of the nonmetal to “ide.”

3. Put a Roman numeral between the metal and nonmetal in parentheses to

represent the valence state.

a. CoCl2 ________________________________

b. OsS2 ________________________________

c. NiO ________________________________

d. NbI3 ________________________________

e. MoBr5 ________________________________

Binary Covalent Type III Compounds: Compounds involving just two nonmetals

1. Write names of the elements as seen changing the ending of the second element to “ide”.

2. Begin the elements with the appropriate prefix.

3. Exception: Do not start the first element with “mono.”

a. NO2 ________________________________

b. CI4 ________________________________

c. P2O5 ________________________________

d. SO2 ________________________________

e. NF3 ________________________________

To write the formula of these types of compounds: 1. Write the elements as seen.

2. Use the prefixes to determine the subscripts. 3. Do not balance charges.

a. Nitrogen Trioxide: __________

b. Silicon Tetrafluoride: __________

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Additional Binary Mixed Review:

a. ClF5 ________________________________

b. Na2S ________________________________

c. FeO ________________________________

d. CoF3 ________________________________

e. AlP ________________________________

f. BeH2 ________________________________

g. PbF2 ________________________________

h. CS2 ________________________________

i. BF3 ________________________________

j. CrS3 ________________________________

k. KF ________________________________

l. N2F4 ________________________________

a. Lithium Bromide __________

b. Calcium Fluoride __________

c. Copper (I) Sulfide __________

d. Phosphorus Pentachloride __________

e. Beryllium Hydride __________

f. Nickel (III) Oxide __________

g. Dinitrogen pentahydride __________

Polyatomic Compounds: These compounds are treated the same as binary compounds except we consider the polyatomic ion as a single element.

a. K2Cr2O7 ________________________________

b. H2O2 ________________________________

c. Ca(OH)2 ________________________________

d. Co(ClO3)2 ________________________________

a. Nickel (III) Phosphate: __________

b. Lithium Oxalate: __________

c. Potassium Arsenate: __________

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Acids:

Naming the acids:

1. If it is binary, then begin the name with “hydro,” and change the ending of the second element to “ic.”

2. If it contains oxygen, do not include the “hydro” in the name.

a. If the polyatomic ion has an “ate” ending, change the ending of the acid to “ic.”

b. If the polyatomic ion has an “ite” ending, change the ending of the acid to “ous.”

1. Name the following acids:

a. HI ________________________________

b. H2CrO4 ________________________________

c. H2S ________________________________

d. HClO4 ________________________________

e. H3AsO4 ________________________________

f. HClO ________________________________

Writing formulas for acids: All of these acids start with an “H.” 1. If it starts with “hydro” then the acid is binary.

2. If the acid does not have the “hydro” beginning, then use the “ic” and “ous” endings to determine the “ate” and “ite” endings.

3. Balance charges.

2. Write the formula for the following acids:

a. Nitric Acid: __________

b. Hydrobromic Acid: __________

c. Hydrochloric Acid: __________

d. Oxalic Acid: __________

e. Perchloric Acid: __________

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Lewis Structures and Molecular Shapes:

Octet Rule: Compounds form bonds so that each element can have 8 valence electrons. Exception: Hydrogen and helium only need 2 valence electrons to be stable.

Simple Examples:

1. HCl

2. SiF4

3. H2O

4. F2

Rules:

1. Draw the central atom (closest to carbon) with the other elements branching out. 2. Sum the total number of valence electrons.

3. Distribute the electrons so that each element has an octet (hydrogen being the exception)

4. Use multiple bonds when needed.

Examples:

1. H2O revisited

2. O2

3. N2

4. CO2

5. NH3

6. CH4

Determining Shapes:

1. If the compound has 2 atoms, the shape is linear.

2. If the compound has three parts and the central atom has no unshared electrons, it is linear.

3. If the compound has three parts and the central atom has unshared electrons, the shape is bent.

4. If the compound has four parts and the central atom has no unshared electrons, the shape is trigonal planar.

5. If the compound has four parts and the central atom has unshared electrons, the shape is pyramidal.

6. If the compound has five parts the shape is a tetrahedron.

Determine the shapes of the examples above.

1. ______________________________

2. ______________________________

3. ______________________________

4. ______________________________

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Hydrocarbons (Extension): Draw the Lewis structures for the following compounds: a. CH3CH2OH

b. C5H12

c. C2H4

d. C2H2

e. Diphosphorus tetrafluoride

Review:

2. Name the following compounds, draw their Lewis structures, and indicate the molecular shape:

a. BF3

b. CBr4

c. NF3

d. NH3

e. HCN

3. Write the formula for the following compounds, draw their Lewis structures, and indicate the molecular shape:

a. Silicon tetrachloride

b. Phosphorus trihydride

c. Sulfur dioxide

d. Sulfur difluoride

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Mixed Review:

1. Name the following compounds: a. Li2HPO4

b. H2SO3

c. Al(ClO4)3

d. NaBr

e. FeC2O4

f. Cu3AsO4

g. NH4Cl

h. Hg2O2

i. P3O5

j. Si2H6

2. Determine the formulas for the following compounds: a. Nitric Acid

b. Iron (II) fluoride

c. Aluminum sulfide

d. Diphosphorus pentahydride

e. Phosphorus trichloride

f. Hydrosulfuric acid

g. Calcium phosphide

h. Cobalt (III) oxide

i. Beryllium carbonate